Transmission synchronizer



Aug. 3,' 1943. w. B. OSBORNE TRANSMISSION SYNCHRONIZER FiIed June 1, 1942 v Patented Aug. 3, 1943 v. 7 2,325,373 TRANSMISSION SYNCHRONIZER I Q 'Wiiliam B.- Osborne; Muncie, Ind assignonto V Borg-Warner Corporation,

1 poration of Illinois hammerin 1, 1

Chicago, 111.; a cor- 8 claims. (01. 192-53) This invention relates to transmission synchronizers of the type in which a jaw clutch sleeve is drivingly mounted on one of aj pair of torque transmitting members to be synchroe nized and is axially shiftable. thereon 1; into clutching engagement with a positive clutch element carried by the other .of said members, synchronizingv means being interposed between the sleeve and the'otherv member andurged. into synchronizing engagement with the 'latter through the medium of" prevents the completion'ofithe shift untilsynchronism has been. established betweenji sai d torque transmitting members.

In the synchronizer with which the present invention dealsparticularly, theLbIQCk-L mgmeans is in the form of approximately three'or more'lugs blocking means which formed on thering and'adapted,-innon-blocking position, to be receivedin recesses or passes in the clutch sleeve, so as to permit the s'leeveto advance to clutching position. In the pa'st, considerable difficulty has beenexperiencezdiwithHthis'type of. synchronizer,..in*.t hat the alignmentllotthe blocker lugs with the. slots; and the consequent movement of .the sleeve'into. engagement with V the jaw clutch teeth .of thecQacting clutch ele mentwould usuallyoccur at'fan instant when the jaw clutch teethrwere notiin registryi-witn-the spaces between the teeth of the sleeve. Chamfers were provided on the engaging ends; of the teeth of the sleeve and jaw clutch element respectively so that the axial pressure of the Ps1eev'e; teeth against thercoacting jawclutch teethQWould tend to rotate the parts relative to each other until the properalignment had been achieved However, such rotation wasre Lsted bythe gripping engagement between the frictionsurfaces-of the synchronizer ring and the coacting cone, and; in order to effect-the alignment of theclutching teeth, it was necessary to break th grip of the frictionsurfaces. 3

The object of the present ,inv ition isto provide, in a synchronizer of the type discussed above, an arrangement permitting the-la clutch teeth to be properly alignedwithout disengaging the iriction surfaces. H p

These andi-other objects and features oigt-he invention will become. apparent from the follow.- ingdetailed description when taken together with the accompanying-drawingin which? Fig. ,1 is a transversesectional View of a pore tion of a synchronizer-embodying .theinvention.

of the synchronizer, the blocker shown in non-blocking position. j

Fig. 4 is a similar; view showing 'thejbloelgerring in an advanced s't'ageof movement :able jaw clutch sleeve.

'As an; example, of one of "the shiftform in which the 'in- .vention may be embodied I have'shownin the drawing a portion of asynchronizer embodiedin r a transmission having a drive shaft l0, a-driven shaft H piloted as at- JZjintherear end ojthe journalled through the medium of a bearing bushing on the driven shaft ll andadapted to receive-"drive from a countershaft' gear cluster (not shown) which in turn is driven from azgear l5-onthe-drive shaft.v

drive shaft l0; and a gear I3 The shaft 1 I is adapted to receive areduced ratio drive from the-countershaft driven gear 13 through the medium of a jaw clutch sleeve it which isshiftable into engagement with positive clutch teeth I!- formed on drive from the drive shaft the gear I3. ,A direct lfi-to the driven shaft H may be established byshifting the sleeve 15 into .engagementwith clutch teeth It formed on the driveshaft' The sleeve {6 "has-internal teeth-i I9 which are 'adaptedto mesh with either the teeth llor theteeth l8;

, integrally with the second'ispeed' gear i3.J "The 4.

Fig. 2 is anaxialsectional view of theisame,

taken'ontheline 2- 2 oiFig. Fig. 3 is a dctailrplan view of interior: -pa-r ts The sleeve 7 i6 is mounted upon a hub 20, the

with external t-eeth' 2| on the hub ZiL Wherebythe sleeve-is drivingly j connected tothe hub;and yet .may be shifted axially soas to establish clutching connection teeth l9 being meshed with the teeth ii or theteeth 18.1. The hub 29 inturnis splined as at 22, upon the driven shaft 'H and, thereby drivingly'connected'thereto-while being free to shiit axiallysufficiently'to establish the synchronizing action which will hereinafter bedescribed; 7

. Mounted an axially Q opening annular dejp s oh 3 in t e 1111191295 i 9l?Q }i PIiI. 1 r 24 having an internal,,thread d;.conical;frictio-n face 25 adapted to coact'with-an externalconical frictioniace 26 on a friction cone' ,2l formed synchronizer ringfi is retained: in the recess '23 by a retainer ring 28;.corifind in annular v ,reces529 in the hub 29. :Thering- ZB retains the synchronizer ring 24in axially-fixed 'relationto the hub 20 but permits it to-oscillate relative to the: hub. Formed on the blocker ring 241*,are

tremities of the sleeve teeth l9.

,Inthe rim32 of the;

'riphery of the reces's23,"are;iormed a pluralityoi "of which are formed on -bloe'kin'g position *as a result ,aoi. axial pressure exertedbythe 'sleeve IB-asiit is-urged towarden- -=chron'izer rgmgwnenecessary axial thrust for whereby the rotation [of the members is amaze engagement the f-riction siirfacesw'iii" finen'tarily estabiish a fiiie'd relation-between H e relativegotation' between-the 'sie'eve it by providing in the 'iiiterier tr he'isle notches 33. The blocker lugs 39 extend through the notches 33 and thence into notches 3! in the end of the sleeve IS. The notches 3! are defined by diverging cam faces 34 the inner extremities pairs of spaced teeth lQa, the latter comprising the blocker portions of the sleeve l6. Each pair of teeth 19;; define between them-a pass 45 adapted ,to receive the correspondingflug EB-ivhen the latter is in "register therewith (non-blocking position shown in l ines n 3), whereby to permit the sleeve It to advance into clutching engagement with the teeth I I. The notches 33. are widerthah'the lugs 39 so as to permit thetlatter to oscillate from the non-blocking position to a position in which one side of eachlug 30'bloc'1is the'path of axial movement of a tooth Ilia. Thus the sleeve l 6 will be blocked against movement intoc1utching engagement with the teeth H. The lugs 38' will be moved to blocking position onone side ob or the 'othero'f the pas sesf45 as 'a'result of frictional engagement between thesurfaces and 2 6- transmitting torque to the ring from the: cone '2'! as long 'as difie'reritlal rotation exists.

The lugs 39 are provided withch'ai'iifered-Iiaces ES-adaDted'to coactwith'the cam'iaces 34":of :the notches '31 -to' urge the lug's'back toward new gagement with the teeth 1.

V The blocking en agement between the lugs .-and-'sleeve' I6-serves notionl-y to block the sleeve from incitement to clutching positienbut also serves "to trsns'maprmm the sleeve to th'esyntightening the friction surfaces 25 and rite synchronizing{engagement with each other,

is synchronized; c I

- Ifprovi de a plurality of poppet bails-35 jdisposed in bores 31fin the hub 2i! 'andui'gedhy coil'springs s'e into engagement with note-hes" 39 infthe teeth ifi er the sleeve [5. The poppet balls 35 are adapted tO trahSmit-"ir'o'inWIie 's eve is to the hub 20 just su'fiicient th 'rus'tto 4 'the'huh ii'ntil tlie' eng'agementbetween the friction faces 25 and 2G is established,thereii-ycaus ing the locker lugs B9 to 'ass'iuine-:their blockingposition, T 4

Upon the es'tablishment DLSynclirQYQL-m, the

"teeth when the lugs tease in their centered, noh-hloekingpositionsY It is necessary then in order to establish theproper alignment of the clutch teeth tofeifect slight a the gear ltfTothiseiid, opposed ends-of the teeth Hand 19 arecl'iam fered as at t t and}? respectively soas to develop"acircuinierential*bias fiom the axial pressure eierted by the "sleeve. In

Theprsent ihventionovercomes his fairs iii a series-of recessesflii each communicating with -eumferthe recesses 43 begin immediately adjacent the inner extremities of the notches 3| and extend sufficiently toward the other side of the sleeve to accommodate the lugs 30 throughout the movement of the sleeve into clutching engagement with the teeth [1.

As soon as the lugs 30 have passed through the passes in such movement of the sleeve 16, they are permitted to move circumferentially in the recesses 43 so as to enable the'synchronizer ring and the clutch teeth I? to move circumferentially without breaking the grip of the frictfoh surfaces, until the teeth I! are in proper alignment with the spaces between the teeth [5 The parts are so arranged that such circumfei iitial adjustment occurs prior to the engagement of the teeth I} by the teeth I9. 7

The blocker lugs 36 are provided with chainfered faces 44 on the outer side thereof, adaptdwlin the sleeve I 6 is retracted from the teeth 11 toguid'e 'the'lugs30 backsthrough the passes In order to form the passes, :axiallyiextends ing slots 45 are "milled in the interior Offthe sleeve 16,.re'moving some of :the teeth .19. 1

A convenient method of forming. thewrecess 43 is to mill it' with 'a icutter having, a diameter 7 smaller than the interior'diameter ofthe sleeve,

so't'hat the recess is arcuate with the circumferential extremities thereof terminating inner- 7 malsurfaces ofthete'ethlil.

While I have described my mason meannection with one specific embodiment, thereof,

' it is to be llXldBIStOOdfthEt this is by way of iliust'ration and not by wayof limitation, and the scope of my inventlon is defined solely ;by the appended claims Whichshould be construed as a broadly a'sthe priol' "art'will permit.

'1 claim? e 1. A transmission synchronizer comprising driving and. driven =fnenibers,. one :of said. membei's having clutch teeth and a friction clutch element, a clutch sleeve inountedr'on, driving'ly connected to and'a'xially shiftable on "thmdther .of said iiiembers and having teeth for engage- Ine'nt 'withls'aid clutch teeth, a synchronizer ele;

ment having a friction surface forco'a'ction with sain' rrietion element, and including "a blocker portionadapted to have limited circumferential movement 'relativeto said 'sleve, said sleeve having a piojectirig' p cirtion "adapted to engage said blo'ckerportion in one position of said'cir'cum fer j eiitia-l movement and definin goneside'of apass adapted to receive said blocker 'portion as thesleeve moves toward clutching engagement i-w'ith setit lfcliitch tee tl'i;"said sleeve having a i'css' 'X- tendiilg cirtumrernnauy fidi'h said pass, in whichsaid blocker pbmon ma move circumferentially -rroin said pass in order to permit said sleeve and clutch teeth to become properly aligned for clutching engagementwithdht breaking the ngagement between the saidrntibn sunate and friction element.

2; Ilia, transmission 'Syi ichioiiiZr, dri'v'in'g' aiid driven {members one of said members having clutch teeth and a friction clutch "nemesis a clutch sleevedrivingly connected to-snd axially sniftabie on the other of "said members ann' having teeth or "meshing eng'aemeatwith said clutch teeth, said-sleeve -'Iia vi"n'g"a pair 6f blocker portions spaced' 'circumferentia3r 'to define a pass, a synchronizer element navinga friction face for coactie'n witns'aid friction 'eimerit and including a blocker'-'1e1i!erit; s83id synchro rii'zer element being itdaii-it'ed to liave liniited circumferential movement relative to said sleeve from a position inwhich it is adapted to be engaged by I one of said sleeve blocker portions to block the movement of said sleeve to clutching engagement with said clutch teeth, to a position in which it is adapted to enter said passso as to permit the sleeve to advance to clutching position, said sleeve being provided, interiorly of said blocking portions, with a recess extending circumferen- 'tially from and communicating with said pass, in which said blocker element may move circumferentially after having moved through said pass,

whereby to permit said clutch teeth and sleeve teeth to properly align themselves for clutching v engagement without breaking the grip of-said friction surfaces. I V a 3. A transmission synchronizer as defined in the preceding claim, wherein said sleeve blocker 7 portions are provided with inclined camming faces adapted to guide said blocker element into said pass in response to axial pressure of the sleeve against said blocker element.

4. A transmission synchronizer as defined in the second preceding claim, wherein said blocker element has chamfered faces adapted to coact with the inner extremities of said sleeve blocker portions so as to guide said blocker elements back into said pass from said recess under axial pressure of said sleeve in the direction of disengagement of said teeth.

5. In a transmission synchronizer, a driving member having clutch teeth and a friction clutch limited circumferential movement, having arradiallv outwardly extending I blocker element adapted inone position of said circumferential movement to, block the path of axialr movement of, one of said sieeve blocker portions and in another position of said circumferential movement to enter said pass so as to permit thesleeve to advance to clutching engagement with said a clutch teeth, said sleeve having, interiorly of said blocker portions, a recess extending circumferentially from and communicating with] said pass and adapted, when said lug has passed through said pass, to receive the lug and permit limited circumferential movementthereof so as to allow said sleeve teeth and clutch teeth'toproperly-align themselves without breaking the engagement of said friction surface and friction elements.

6. A transmission synchronizer as defined in the preceding claimwherein said hub is provided with an annular recess and wherein said synchro V nizer element is in the form of a ring having a portion journalled in said recess, saidsynchronizer including a snap ring' confined in said recess and in turn confining said ring in'said recess.

'7. A transmission 'synchronizer as definedin,

the second preceding claim, wherein said hub has a rim defining an annular recess, wherein said synchronizer element is in the form of a ring having a portion journalled in said recess, and

wherein said rim is provided with an axially opening notch through which'said blocker'element extends radially outwardly, contact of the '7 circumferential extremities of said lug with the extremities of said rim defining said notch serving to limit said circumferential movement.

8. A transmission synchronizer as defined in claim 2, wherein said recess isarcuate,

' WILLIAM 13.: osnoaNn. 

